Teeny weeny jawbone ID

vole-woman · #1 (**permalink**) 02-05-2009, 02:35 PM

I broke up some sort of raptor pellet while I was out on Whixall Moss this afternoon, and found this jawbone. Is it shrew? I thought shrews had re-tipped teeth, but the incisors don't look rodenty enough for a mouse or vole.

(Ooh, and I saw a stoat!!!

First one in years! Only a flash, though.)

Dogghound · #2 (**permalink**) 02-05-2009, 09:27 PM

Its from a mouse, most likely a wood mouse. The part that connects with the skull (other end to the teeth), has two points . In mice/rats the gap between them is a shallow indent, in voles it is a deep indent.

vole-woman · #3 (**permalink**) 02-05-2009, 09:30 PM

Thanks! I thought mice had flat incisors like voles, not pointed ones.

Dogghound · #4 (**permalink**) 02-05-2009, 09:37 PM

How do you mean flat? Both field vole and water vole lower incisors are pointed. Bank voles are more flat. All rodent incisors still go to a point. Ive just compared this one to ones ive got and im almost certain its from a woodmouse.

vole-woman · #5 (**permalink**) 03-05-2009, 07:43 AM

I suppose I was thinking about upper incisors, which to me looked spade-shaped, like my own and like Bugs Bunny's. I really need to do some small-mammal trapping, don't I? I do all this work looking at field signs and habitat, and it's a red letter day if I glimpse an actual mammal from a distance. I could do with getting very close to something and having a good look.

The Woodman · #6 (**permalink**) 03-05-2009, 08:27 AM

You could also try to pull out the largest molar (the one nearest the gap between it and the insicors) from the jaw bone. The resultant holes from the tooth roots will give you a clue. If they look like 4 pin holes they will be wood mice, 3 -House Mouse.

If the molar leaves one large hole, it will be from a vole.

Also, have a go at pulling out an incisor. They are near semi-circular and cannot be pulled straight out. They are very long teeth and you will be aable to see how the jaw accepts the teeth and how far the socket goes into the jaw bone.

Get yourself booked on one of the Mammal Societies mammal ID courses. There is a good one this year at FSC's Preston Montford, Shrewsbury, not too far from you, led by one of the countries finest mammal experts.

Congratulations on 1000 posts!

vole-woman · #7 (**permalink**) 03-05-2009, 08:38 AM

Oh, thank you!

Great advice re molars etc. I've a dim recollection of doing that when I was in my early teens and staying with the family in Watchet who had the barn owls, but I'd forgotten about it till you said.

I was looking the other day at the mammal trapping course in Shrewsbury, but the one I wanted to go on was when I was abroad on holiday, and also I wasn't sure whether I should sign up for beginners or the next stage up. Given my ignorance on the subject of incisors, I've probably answered my own question there! I really want to do a course there, though.